1. Field of the Invention
The present invention relates to a copying machine employing an electrophotographic process and, more particularly, to a copying machine capable of edit-copying.
2. Description of the Prior Art
There has been proposed an electrophotographic copying machine capable of so-called edit-copying function for forming a blank area, corresponding to a specific area on a document, on a copying paper.
Such a conventional electrophotographic copying machine having edit-copying function is based on a principle of omitting the reproduction of an area undesired to be copied or an area to be blanked in a document by eliminating electric changes in the area on the photosensitive member corresponding to the undesired area to be copied or the area to be blanked in the document prior to developing the electrostatic latent image, thus the toner attraction to the area on the photosensitive member is prohibited.
However, such a conventional copying machine does not fulfil the following two requirements.
When copies of a document are to be distributed, a portion of a copy corresponding to a specific area of the document should be highlightened. For that purpose, it is a usual practice to underline the part on the document or on the copies.
Further, copying machines are recently required to print simple data such as date in addition to the image of a document. In such a case, it is a usual practice to enter a desired data on the document before copying the same or to enter the desired data on the copies of the document.
Writing data or underlining on the document spoils the document while writing data or underlining on copies requires much labor when many copies of the document are needed.
Therefore, such a copying machine is required to be capable of making a portion of a copy corresponding to a specific area of the document highlightened without sufferring from said drawbacks, more specifically, capable of giving suitable contrasts among areas of the copy corresponding to the areas of the document, when those areas have different degrees of importance.
It is also required to introduce a copying machine capable of forming characters on a copying paper readily without an input device, such as a word processor keyboard which requires significant modifications on the copying system.